1. Field of the Invention
The present invention relates to a motor and, more particularly, to a motor including a balancing member for stabilizing rotation of a rotor of the motor.
2. Description of the Related Art
Motors with a balancing member have been proposed, and an example is disclosed in Taiwan Patent Publication No. 423760 entitled “Brushless D.C. Motor”. As shown in FIG. 1, such a motor 9 includes a base 91, a stator 92, a rotor 93, and a balancing plate 94. The base 91 includes an axle tube 911 around which the stator 92 is fixed. The rotor 93 includes a shaft 931 rotatably extending through the axle tube 911 and a permanent magnet 932. The balancing plate 94 is mounted to the base 91, with a magnetically attracting spacing D formed between the balancing plate 94 and the permanent magnet 932 to provide a magnetically attracting effect therebetween, so that the rotor 93 can rotate stably.
The magnetically attracting spacing D is one of the main factors affecting the stable rotation of the rotor 93. Specifically, if the magnetically attracting spacing D is too large, the magnetically attracting effect between the balancing plate 94 and the permanent magnet 932 could be too small, such that the rotor 93 could not rotate stably, leading to wobbling of the rotor 93 and noise and shortening the service life of the motor 9. On the other hand, if the magnetically attracting spacing D is too small, the magnetically attracting effect between the balancing plate 94 and the permanent magnet 932 could be too large, such that rotation of the rotor 93 could be adversely affected. Furthermore, operations of the permanent magnet 932 and the balancing plate 94 could interfere with each other, adversely affecting operational performance of the motor 9.
Thus, a need exits for a motor having an optimal spacing between the balancing plate and the permanent magnet to avoid problems encountered in the conventional motors and to assure stable rotation of the rotor.